A supplemental fuel system includes a supplemental fuel tank, an electronic valve, a temperature sensor, and a controller. The supplemental fuel tank is configured to store a supplemental fuel configured to supplement a primary fuel used by an engine. The electronic valve is configured to be positioned between the supplemental fuel tank and an air supply system for the engine. The temperature sensor is configured to acquire temperature data regarding a temperature of the engine. The controller is configured to control the electronic valve such that the electronic valve is (i) closed to prevent the supplemental fuel from being provided to the air supply system in response to the temperature being less than a temperature threshold and (ii) open or openable to permit the supplemental fuel to be provided to the air supply system in response to the temperature being greater than the temperature threshold.

A supplemental fuel system includes a supplemental fuel tank, an electronic valve, a temperature sensor, and a controller. The supplemental fuel tank is configured to store a supplemental fuel configured to supplement a primary fuel used by an engine. The electronic valve is configured to be positioned between the supplemental fuel tank and an air supply system for the engine. The temperature sensor is configured to acquire temperature data regarding a temperature of the engine. The controller is configured to control the electronic valve such that the electronic valve is (i) closed to prevent the supplemental fuel from being provided to the air supply system in response to the temperature being less than a temperature threshold and (ii) open or openable to permit the supplemental fuel to be provided to the air supply system in response to the temperature being greater than the temperature threshold.

A controller and a control method for internal combustion engine, and a memory medium are provided. A port injection ratio is changed according to an engine operating state of the internal combustion engine. The port injection ratio is a ratio of a port injection amount that is an amount of fuel injected by port injection valves to an amount of fuel supplied to cylinders from the port injection valves and direct injection valves. An injection reducing process causes a fuel injection amount in a reduced-injection cylinder to be smaller than a fuel injection amount in other cylinders. An increase limiting process limits increases in an adhered fuel amount in intake ports by regulating the port injection ratio during execution of the injection reducing process.

A controller and a control method for internal combustion engine, and a memory medium are provided. A port injection ratio is changed according to an engine operating state of the internal combustion engine. The port injection ratio is a ratio of a port injection amount that is an amount of fuel injected by port injection valves to an amount of fuel supplied to cylinders from the port injection valves and direct injection valves. An injection reducing process causes a fuel injection amount in a reduced-injection cylinder to be smaller than a fuel injection amount in other cylinders. An increase limiting process limits increases in an adhered fuel amount in intake ports by regulating the port injection ratio during execution of the injection reducing process.

In a method of removing particles in an injector of a diesel engine, a stop of the diesel engine may be recognized. An injection signal may be inputted into the injector of the stopped diesel engine. A control valve of the injector may be moved in a low-pressure passage by the injection signal to remove the particles accumulated on an inner wall of the low-pressure passage. Thus, a malfunction of the control valve caused by the particles may be previously prevented.

In a method of removing particles in an injector of a diesel engine, a stop of the diesel engine may be recognized. An injection signal may be inputted into the injector of the stopped diesel engine. A control valve of the injector may be moved in a low-pressure passage by the injection signal to remove the particles accumulated on an inner wall of the low-pressure passage. Thus, a malfunction of the control valve caused by the particles may be previously prevented.

Methods and systems are provided for balancing a plurality of fuel injectors via a diagnostic. In one example, a method may include adjusting a fuel injection pattern to increase an occurrence of a fuel injection being preceded by a same-cylinder bank fuel injection. The method may further include skipping fuel injections resulting in the fuel injection being preceded by an opposite-cylinder bank fuel injection.

Methods and systems are provided for balancing a plurality of fuel injectors via a diagnostic. In one example, a method may include adjusting a fuel injection pattern to increase an occurrence of a fuel injection being preceded by a same-cylinder bank fuel injection. The method may further include skipping fuel injections resulting in the fuel injection being preceded by an opposite-cylinder bank fuel injection.

A supplemental fuel system includes a supplemental fuel tank, an electronic lock off valve, a temperature sensor, and a controller. The supplemental fuel tank is configured to store a supplemental fuel. The supplemental fuel is configured to supplement a primary fuel used by an engine. The electronic lock off valve is configured to be positioned between the supplemental fuel tank and an air supply system for the engine. The temperature sensor is configured to acquire temperature data regarding a temperature of exhaust gas output by the engine. The controller is configured to control the electronic lock off valve such that the electronic lock off valve is (i) closed in response to the temperature being greater than a temperature threshold and (ii) open or openable in response to the temperature being less than the temperature threshold.

A supplemental fuel system includes a supplemental fuel tank, an electronic lock off valve, a temperature sensor, and a controller. The supplemental fuel tank is configured to store a supplemental fuel. The supplemental fuel is configured to supplement a primary fuel used by an engine. The electronic lock off valve is configured to be positioned between the supplemental fuel tank and an air supply system for the engine. The temperature sensor is configured to acquire temperature data regarding a temperature of exhaust gas output by the engine. The controller is configured to control the electronic lock off valve such that the electronic lock off valve is (i) closed in response to the temperature being greater than a temperature threshold and (ii) open or openable in response to the temperature being less than the temperature threshold.